.com & .net are definitely the more recognised ones (the biggies). But for infomation site, personally I won't mind going for .info instead of a .net. .biz fit well for words like hotdog.biz, designart.biz etc. .org fits perfect for non-profit organisation for which you'll most likely not sell (domain) for a profit. I personally find it hard to find the right .tv and .nu, and also their high reg fees kinda turned me off. .us is rather broad, suitable for anything in the States. Depending which word, they have different potentials.